Benchmark: Compare performance between Dayjs.tz and Temporal.ZonedDateTime

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/dayjs@1/dayjs.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/dayjs@1/plugin/timezone.js"></script>
<script src="https://cdn.jsdelivr.net/npm/dayjs@1/plugin/arraySupport.js"></script>
<script src="https://cdn.jsdelivr.net/npm/dayjs@1/plugin/utc.js"></script>
<script src='https://cdn.jsdelivr.net/npm/temporal-polyfill@0.3.0/global.min.js'></script>

Script Preparation code:

dayjs.extend(window.dayjs_plugin_timezone);
dayjs.extend(window.dayjs_plugin_arraySupport);
dayjs.extend(window.dayjs_plugin_utc);

Tests:

Create a Dayjs.tz
dayjs.tz([2025, 7, 1], "Europe/London").endOf("month");
Create a Temporal.ZonedDateTime
const dt = Temporal.ZonedDateTime.from({ year: 2025, month: 8, day: 1, timeZone: "Europe/London" }); dt.with({ day: dt.daysInMonth, hour: 24, minute: 59, second: 59, millisecond: 999 });

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Create a Temporal.ZonedDateTime

182K/s

Create a Dayjs.tz

22K/s

Fastest: Create a Temporal.ZonedDateTime (8.4x faster)

View exact numbers

✓ Create a Temporal.ZonedDateTime: 182,498 ops/sec
• Create a Dayjs.tz: 21,715 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Create a Dayjs.tz
Create a Temporal.ZonedDateTime

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 months ago)

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:145.0) Gecko/20100101 Firefox/145.0

Browser/OS: Firefox 145 on Ubuntu

View result in a separate tab

Create a Temporal.ZonedDateTime

55K/s

Create a Dayjs.tz

5K/s

View exact numbers

Test name	Executions per second
✓ Create a Temporal.ZonedDateTime	54,611 Ops/sec
Create a Dayjs.tz	4,817 Ops/sec

Compare performance between Dayjs.tz and Temporal.ZonedDateTime (version: 6)

Get the end of month of an arbitrary month with both.

Comparing performance of: `Create a Dayjs.tz vs Create a Temporal.ZonedDateTime`

Created: one year ago by: Registered User

Go to the latest result

Create a Dayjs.tz

Create a Temporal.ZonedDateTime

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Compare performance between Dayjs.tz and Temporal.ZonedDateTime (version: 6)

Get the end of month of an arbitrary month with both.

Comparing performance of: Create a Dayjs.tz vs Create a Temporal.ZonedDateTime

Created: one year ago by: Registered User

Go to the latest result

Create a Dayjs.tz

Create a Temporal.ZonedDateTime

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `Create a Dayjs.tz vs Create a Temporal.ZonedDateTime`